Pelvic Fields Research Articles

Adjuvant Therapy on Cancer of the Lower Rectum. Evaluation of the Effects of Preoperative Radiotherapy on the Prognosis of Patients with Cancer of the Lower Rectum

Aims: The prognosis on treatment of the cancer of the rectum has not changed in the last fifty years. Survival rates of 50 to 55% seems immutable in several published series. The main cause for those results is the high incidence of recurrence, either local or widespread. Local recurrence is directly related to the number of undifferentiated cells and to the grade of wall invasion. Widespread recurrence depends specifically on the lymphatic and vascular spreading. So any kind of treatment that would diminish the number of undifferentiated cells and the size or the tumor wall penetration would certainly decrease the local recurrence rate, lengthening the interval free from cancer and, perhaps, modifying the long term survival rate. Between 1978 and 2009, a total of 538 patients with adenocarcinoma of the lower rectum (from the pectinate line to 10 cm above) were treated by preoperative radiotherapy. Methodology: The same protocol was used in all the patients – 400 cGy, 200 cGy/day, during 4 consecutive weeks (anterior and posterior pelvic fields) by means of a Linear Megavoltage Accelerator (25 MeV). Surgery was performed 2 months after completion of the radiotherapy. Results: Statistical analysis of the whole group showed that preoperative radiotherapy does decrease frequency of undifferentiated cells. Moreover, the incidence of local recurrence diminished after irradiation by 3.4%. Preoperative radiotherapy reduces tumor volume (ERUS) and wall invasion, as well as the mortality rate due to local recurrence (2.4%) and alters long-term survival rate (80.1%). Conclusion: Preoperative radiotherapy is really effective in reducing the number of undifferentiated cells and in diminishing the tumor volume and the carcinomatous infiltration of the rectal wall.

Matrix metalloproteinase-8 mediates the unfavorable systemic impact of local irradiation on pharmacokinetics of anti-cancer drug 5-Fluorouracil.

Concurrent chemoradiation with 5-fluorouracil (5-FU) is widely accepted for cancer treatment. However, the interactions between radiation and 5-FU remain unclear. Here, we evaluated the influence of local irradiation on the pharmacokinetics of 5-FU in rats. The single-fraction radiation was delivered to the whole pelvic fields of Sprague-Dawley rats after computerized tomography-based planning. 5-FU at 100 mg/kg was prescribed 24 hours after radiation. A high-performance liquid chromatography system was used to measure 5-FU in the blood. Matrix metalloproteinase-8 (MMP-8) inhibitor I was administered to examine whether or not RT modulation of 5-FU pharmacokinetic parameters could be blocked. Compared with sham-irradiated controls, whole pelvic irradiation reduced the area under the concentration versus time curve (AUC) of 5-FU in plasma and, in contrast, increased in bile with a radiation dose-dependent manner. Based on protein array analysis, the amount of plasma MMP-8 was increased by whole pelvic irradiation (2.8-fold by 0.5 Gy and 5.3-fold by 2 Gy) in comparison with controls. Pretreatment with MMP-8 inhibitor reversed the effect of irradiation on AUC of 5-FU in plasma. Our findings first indicate that local irradiation modulate the systemic pharmacokinetics of 5-FU through stimulating the release of MMP-8. The pharmacokinetics of 5-FU during concurrent chemoradiaiton therapy should be rechecked and the optimal 5-FU dose should be reevaluated, and adjusted if necessary, during CCRT.

SU-E-T-526: Is the Marker Matching Method Adequate for Daily Setup of Pelvic Fields in Prostate Irradiation?

Purpose: It is common practice to implant fiducial markers and to perform daily setups based on these markers in delivering radiation to prostate. When the pelvic nodes are also treated, the fields are significantly larger and extend superiorly. Will it still prove adequate to align these fields based on the marker matching method? Alternatively, if we choose to align the fields relative to bony anatomy, will the prostate PTV be adequately covered? The current study attempts to carefully examine these problems. Methods: We choose to use a 2D/2D match for the pelvic nodal irradiation and to use marker matching for the cone‐downs. Daily orthogonal setup KV images for 20 patients, over the course of pelvic nodal irradiation ranging from 25 to 28 treatment, are first matched to bony anatomy, then to contours of the markers, which are delineated during the planning process. The differences between these two methods were recorded and analyzed. This study assumes that a perfect alignment to the bony anatomy can be achieved. The images showing obvious pelvis tilt were excluded from this study and the misalignment of the patient in coronal direction is corrected by applying pedestal rotation. A total of 466 image pairs were studied. Results: Analysis showed that 121 out of 466 cases (26%) needed pedestal rotation ranging from 0.1° to 2.4°, which cannot be picked up using the marker matching method. Additionally we discovered that the percentage of cases that prostate shifted by more than 5mm, relative to bony anatomy, was 7.73%, 1.07% and 0.0% in the vertical, longitudinal and lateral directions respectively. Conclusions: Marker matching is inadequate for large pelvic field alignment. Pelvic fields should be aligned relative to bony anatomy and, then, if the mismatch between the markers and their corresponding contours exceeds a predetermined threshold, table shifts should be adjusted to compensate.

The prognostic factors in cervical carcinoma treated by radical hysterectomy combined with pelvic radiotherapy.

e15584 Background: Local regional lymp node is the main recurrence site in cervical carcinoma after radical hysterectomy. A retrospective analysis is used to evaluate the efficacy of pelvic radiotherapy and prognostic factors for stage IB-IIB (FIGO Stage) cervical carcinoma initially treated by surgery. Methods: From May 1998 to Dec 2006, a total of 77 patients of cervical carcinoma staged IB-IIB patients were eligible for this retrospective analysis. The diseases were staged IB in 20, IIA in 27 and IIB in 30 patients. All of them received external beam irradiation with 6MV X-ray 50Gy/25 fractions to pelvic field after radical hysterectomy. Overall survival rate was estimated by using Kaplan-Meier method. The prognostic factors were analyzed using univariate (Log rank) and multivariate Cox model. Results: The follow-up time was 5-152 months (median 33 months). The overall 5-year survival rate of stage IB, IIA and IIB were 79.4%, 69.8% and 51.9%, respectively. On univariate analysis, variables significantly associated with positive included age≤35 years (χ2=4.569, P=0.033), anaemia (χ2=4.806, P=0.028), stage≥IIB (χ2=6.120, P=0.013), tumor diameter ≥ 4cm (χ2=8.238, P=0.004)and pelvic lymph node metastasis (χ2=5.582, P=0.018). However in the multivariate analysis, only age ≤ 35 years (χ2=5.637, P=0.018), tumor diameter ≥ 4 cm (χ2=4.377, P=0.036) and pelvic lymph node metastasis (χ2=7.814, P=0.005) were significant factors associated with poorer prognosis. Conclusions: Postoperative adjuvant pelvic radiotherapy can improve the efficacy of patients for stage IB-IIB cervical carcinoma. Age ≤ 35 years, tumor diameter ≥ 4 cm and pelvic lymph node metastasis were confirmed as the independent prognostic factors.

Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

To observe, by retrospective analysis, the curative effects and complications due to californium-252 (252Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with 252Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7-12 Gy per insertion per week, with a total dose of 29-45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16-38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44-56 Gy. The total treatment course was 5 to 6 weeks. Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Results of this series suggest that the combined use of 252Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

Role of matrix metalloproteinase-8 in the modulation of systemic 5-fluorouracil pharmacokinetics by local irradiation.

466 Background: Concurrent chemoradiation with 5-fluorouracil (5-FU) is widely accepted for cancer treatment. However, the interactions between radiation and 5-FU remain unclear. We evaluated the influence of local irradiation on the pharmacokinetics of 5-FU in rats. Methods: The single-fraction radiation was delivered to the whole pelvic fields of Sprague-Dawley rats from a linear accelerator after computerized tomography-based planning. 5-FU at 100 mg/kg was intravenously infused 24 hours after radiation. A high-performance liquid chromatography system equipped with a UV detector was used to measure 5-FU in the blood. Matrix metalloproteinase-8 (MMP-8) inhibitor I was administered to the rats to examine whether or not RT modulation of 5-FU pharmacokinetic parameters could be blocked. Results: Compared with sham-irradiated controls, whole pelvic irradiation reduced the area under the concentration versus time curve (AUC) of 5-FU in plasma and, in contrast, increased the AUC in bile in a radiation dose-dependent manner. Based on protein array analysis, the amount of plasma MMP-8 was increased by whole pelvic irradiation (2.8-fold by 0.5 Gy and 5.3-fold by 2 Gy) in comparison with controls. Pretreatment with MMP-8 inhibitor reversed the effect of irradiation on AUC of 5-FU in plasma. Conclusions: Local irradiation may modulate the systemic pharmacokinetics of 5-FU through stimulating the release of MMP-8. This unexpected influence is worthy of further investigation and for consideration in clinical practice of radiotherapy for cancer. No significant financial relationships to disclose.

Effect of Pelvic Lymph Node IMRT Plans on Calculated Testicular Doses Compared with Prostate Irradiation Alone

Effect of Pelvic Lymph Node IMRT Plans on Calculated Testicular Doses Compared with Prostate Irradiation Alone

Normalization of prostate specific antigen in patients treated with intensity modulated radiotherapy for clinically localized prostate cancer

BackgroundThe purpose of this study was to determine the expected time to prostate specific antigen (PSA) normalization with or without neoadjuvant androgen deprivation (NAAD) therapy after treatment with intensity modulated radiotherapy (IMRT) for patients with clinically localized prostate cancer.MethodsA retrospective cohort research design was used. A total of 133 patients with clinical stage T1c to T3b prostate cancer (2002 AJCC staging) treated in a community setting between January 2002 and July 2005 were reviewed for time to PSA normalization using 1 ng/mL and 2 ng/mL as criteria. All patients received IMRT as part of their management. Times to PSA normalization were calculated using the Kaplan-Meier method. Significance was assessed at p < 0.05.ResultsFifty-six of the 133 patients received NAAD (42.1%). Thirty-one patients (23.8%) received radiation to a limited pelvic field followed by an IMRT boost, while 99 patients received IMRT alone (76.2%). The times to serum PSA normalization < 2 ng/mL when treated with or without NAAD were 298 ± 24 and 302 ± 33 days (mean ± SEM), respectively (p > 0.05), and 303 ± 24 and 405 ± 46 days, respectively, for PSA < 1 ng/mL (p < 0.05). Stage T1 and T2 tumors had significantly increased time to PSA normalization < 1 ng/mL in comparison to Stage T3 tumors. Also, higher Gleason scores were significantly correlated with a faster time to PSA normalization < 1 ng/mL.ConclusionsUse of NAAD in conjunction with IMRT leads to a significantly shortened time to normalization of serum PSA < 1 ng/mL in patients with clinically localized prostate cancer.

Clinical analysis of combination of (252)Cf neutron intracavitary brachytherapy and external beam radiotherapy for 110 cervical cancer patients

To evaluate the curative effect and complication of (252)Cf brachytherapy on cervical cancer. From Nov 2002 to Nov 2007, 110 cervical cancer patients were treated by combination of (252)Cf neutron intracavitary brachytherapy and external beam radiotherapy. There were 2 cases of stage Ib, 5 stage IIa, 57 stage IIb, 2 stage IIIa, 41 stage IIIb, 2 stage IVa, and 1 stage IVb. The whole pelvic cavity was irradiated with 8 MV X-ray, 1.8 Gy/fraction, 4 - 5 times per week. The total dose of external beam radiotherapy was 40 - 50 Gy (the center of whole pelvic field was blocked by 4 cm in width after 20 - 30 Gy). (252)Cf neutron intracavitary brachytherapy was delivered at 6 - 8 Gy(i)/fraction, and the total dose of reference point A was 30-51 Gy(i). The median dose was 42 Gy(i). The overall 3-year survival rate of all patients was 79.2%, and the local control rate was 90.0%. In particular, the 3-year survival rate was 1/2 for stage I, 84.3% for stage II, 53.7% for stage III. The difference between stage II and stage III was statistically significant (P < 0.05). The 3-year survival in cervical lesions larger than or equal to 4 cm and those less than 4 cm was 68.1% and 71.2%, respectively (P > 0.05). The 3-year survival rate of patients with and without anemia was 42.4% and 78.2%, respectively (P < 0.05). The 3-year survival rate of patients with squamous cell carcinoma and adenocarcinoma was 78.5% and 76.9%, respectively (P > 0.05). The late radiation complications of rectum and bladder was 11.8% (13/110) and 2.7% (3/110), respectively. It is concluded that (252)Cf is a better source for intracavitary brachytherapy. According to our initial experience, (252)Cf has advantages of a high local control rate, especially to bulky tumor and adenocarcinoma.

Characteristics and management of erectile dysfunction after various treatments for prostate cancer

Preface Currently, there are many wellestablished therapeutic options for early prostate cancer, and therefore, it is difficult for both urologists and patients to choose the optimal treatment. It is essential for urologists to counsel their patients according to reliable information about the advantages and disadvantages of each therapeutic option. We picked the topic for this issue, “Characteristics and management of erectile dysfunction after various treatments for prostate cancer,” because erectile dysfunction (ED) is one of the most frequent adverse events encountered in the management of prostate cancer. We invited six specialists to review each therapeutic option: radical prostatectomy, laparoscopic radical prostatectomy, robot-assisted laparoscopic radical prostatectomy, external beam radiotherapy, brachytherapy, and androgen deprivation therapy (ADT). Among these modalities, surgical interventions tend to induce a quick drop in erectile function with slow postoperative recovery. Early postoperative rehabilitation has been introduced, aiming at the early recovery of ED. On the contrary, radiation therapy tends to maintain the patient’s erectile function for a while after treatment but it gradually decreases. ADT may compromise not only the erectile function but also the libido level, and may result in significant deterioration of the patient’s quality of life. We hope these reviews will help urologists to counsel their patients with regards to decision-making in the management of early prostate cancer.

Assessment of nodal target definition and dosimetry using three different techniques: implications for re-defining the optimal pelvic field in endometrial cancer

Purposes1. To determine the optimal pelvic nodal clinical target volume for post-operative treatment of endometrial cancer. 2. To compare the DVH of different treatment planning techniques applied to this new CTV and the surrounding tissues.Methods and MaterialsBased on the literature, we selected a methodology to delineate nodal target volume to define a NEW-CTV and NEW-PTV. Conventional 2D fields, 3D fields based on anatomic guidelines per RTOG 0418, 3D fields based on our guidelines, and IMRT based on our guidelines were assessed for coverage of NEW-CTV, NEW-PTV, and surrounding structures. CT scans of 10 patients with gynecologic malignancies after TAH/BSO were used. DVHs were compared.ResultsFor NEW-PTV, mean V45Gy were 50% and 69% for 2D and RTOG 0418-3DCRT vs. 98% and 97% for NEW-3DCRT and NEW-IMRT (p < 0.0009). Mean V45Gy small bowel were 24% and 20% for 2D and RTOG 0418-3DCRT, increased to 32% with NEW-3DCRT, and decreased to 14% with IMRT (p = 0.005, 0.138, 0.002). Mean V45Gy rectum were 26%, 35%, and 52% for 2D, RTOG 0418-3DCRT, and NEW-3DCRT, and decreased to 26% with NEW-IMRT (p < 0.05). Mean V45Gy bladder were 83%, 51%, and 73% for 2D, RTOG 0418-3DCRT, and NEW-3DCRT, and decreased to 30% with NEW-IMRT (p < 0.002).ConclusionsConventional 2D and RTOG 0418-based 3DCRT plans cover only a fraction of our comprehensive PTV. A 3DCRT plan covers this PTV with high doses to normal tissues, whereas IMRT covers the PTV while delivering lower normal tissue doses. Re-consideration of what specifically the pelvic target encompasses is warranted.

A phase III protocol of androgen suppression (AS) and radiation therapy (RT) versus AS and RT followed by chemotherapy with paclitaxel, estramustine, and etoposide (TEE) for localized, high-risk, prostate cancer, RTOG 9902.

4632 Background: High-risk, localized prostate cancer (PCa) is generally treated with a combination of RT and long-term AS. It was our hypothesis that adjuvant CT would improve the survival rate of high-risk PCa when used in combination with RT and AS. Methods: Pts with PSA 20-100 and Gleason score (GS) ≥7 or clinical stage ≥T2 and GS ≥8 were randomized to RT and AS with or without four 21-day cycles of CT, starting 28 days after RT, with oral estramustine 280 mg tid × 14 days, oral VP-16 50 mg/m2 in divided doses bid × 14 days, and paclitaxel 135 mg/m2 iv on day 2. Warfarin was originally given at 1 mg/day during CT, but, after thromboembolic (TE) toxicity was observed, the dosage was increased to keep the INR between 1.5 and 2.5. RT consisted of 46.8 Gy to a small pelvic field followed by a prostate boost of 23.4 Gy for a total of 70.2 Gy. AS consisted of LHRH for 24 mos beginning 2 mos preRT plus oral antiandrogen before and during RT. Results: This study opened in Jan 2000 and closed in Oct 2004 with a total of 397 pts (of a planned 1,440) entered (380 eligible). We previously reported on the TE toxicities that led to early protocol closure (Rosenthal, et al. IJROBP 73:672, 2009), but pts have been followed for the primary endpoint, and we report now overall survival (OS) as well as biochemical failure (BF). Pts had high-risk features: 68% had GS ≥8, median PSA was 24.2, and 33% were cT3. Median FU is 6 yrs. 5-yr OS was 86% for both the RT+AS and RT+AS+CT arms (p=0.79). 5-yr BF rates were also similar: 43% for RT+AS and 48% for RT+AS+CT (p=0.26). Conclusions: RTOG 9902 failed to reach its accrual goal due to toxicity. With 5-yr data, there is no difference in OS observed with the addition of adjuvant CT. No difference in 5 yr BF rates was noted. Sample size reduction because of premature closure may have reduced the ability to detect a significant difference. A similarly designed trial, RTOG 0521, completed accrual in 2009, but CT was delivered with docetaxel/prednisone rather than TEE. Results of RTOG 0521 are pending and may help better define the role for adjuvant CT for high risk, localized PCa pts. Supported by NCI grants U10 CA21661 and U10 CA37422. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration AstraZeneca, Bristol-Myers Squibb, Ferring Pharmaceuticals, Watson Pharmaceuticals Bristol-Myers Squibb

Conformal radiotherapy of prostate cancer: What is the proper technique for sparing organs-at-risk?

The aim of the current study was to evaluate the optimal coplanar technique for conformal radiotherapy of prostate cancer. Twelve inoperable patients with prostatic carcinoma were examined. Five different techniques with three-, four- and six-fields were applied for treatment of prostate and seminal vesicles with or without lymph nodes. Treatment techniques were compared by using rectum, bladder and femoral heads dose-volume histogram data. A three-field arrangement consisting of an anterior and two lateral portals resulted in the maximum rectal sparing irrespectively of the irradiated area. The maximum femoral head sparing was achieved by the technique consisting of six oblique and lateral fields. The maximum bladder protection was observed with the box technique for treatment with large pelvic fields and with the arrangement consisting of two oblique and two lateral portals for conedown irradiation. In conclusion, the presented data allow the radiotherapists to select the proper irradiation technique associated with the maximum sparing of each organ-at-risk.

Laparoscopic-assisted vaginal radical hysterectomy (LAVRH) in recipients of kidney transplant with cervical cancer stage Ib1

The incidence of cancer among patients submitted to kidney transplantation is increasing, since the graft survival rates have improved. Cervical cancer is approximately fivefold more common among these patients, correlated to immunosuppression exposure and antibody response to HPV infection. Treatment is challenging, regarding the graft in the pelvic field and standard options for stage Ib include radical hysterectomy or chemoradiation. We report two patients submitted to kidney transplantation with cervical cancer that were successfully treated by means of surgery. In conclusion, we intended to enlarge the current experience with radical hysterectomy in transplanted kidney patients with early stage cervical cancer. Although surgical difficulties existed, we could attest the feasibility and oncologic safety of the method.

Evaluation of Nodal Coverage for Cervical Cancer by In Vivo Localization of Sentinel Lymph Nodes

To assess coverage of sentinel nodes, as determined by hybrid SPECT/CT scan followed by sentinel lymph node (SLN) dissection, in carcinoma of the cervix by 2D conventional, CT-based 3D conformal (3D-CRT) and intensity modulated radiation therapy (IMRT) pelvic treatment fields. Twenty patients previously enrolled on a prospective trial assessing the role of SPECT/CT scan and SLN dissection in cervical cancer were evaluated. Operative notes, pathology reports, and SPECT/CT scans were used to locate the SLNs. Identified SLNs were then contoured on a representative patient. The initial nodal area was contoured as a 1 cm circle on an axial slice and then volumetrically expanded 0.5 cm axially and 0.75 cm cranio-caudally to create a sentinel node PTV (snPTV). These contours were hidden and 2D conventional (based on bony landmarks: sup. border, L5-S1 interspace; inf. border, obturator foramina; lat. border, 2 cm lateral to pelvic brim; ant. border, symphysis pubis; post. border, behind sacrum), 3D-CRT (based on vessels contours), and IMRT (per RTOG 0418) treatment fields were designed. Adequacy of the treatment fields was determined by whether the treatment field encompassed the snPTV. Of the 20 patients originally enrolled, 18 had evaluable SPECT/CT images. Forty-four SLN (19 right and 25 left) were identified and evaluated. There were 15 external iliac, 11 obturator, 8 internal iliac, 6 common iliac, 3 presacral, and 1 para-aortic SNL identified. Conventional 2D fields inadequately covered the snPTV in 6 patients (33%), representing 6 of 44 (13.6%) of the SLNs. Specifically, 3 common iliac, 2 internal iliac and 1 para-aortic snPTV regions extended outside the treatment portal. In 3 patients (16.6 %), the snPTV extended beyond the superior border of the AP/PA and LAT fields. In 3 patients (16.6%), the snPTV extended laterally outside the AP/PA treatment portal. With 3D-CRT and IMRT, 2 patients (11.1%) had inadequate coverage, representing 4.5% (2 of 44) of the identified sentinel nodes. Of the two inadequately covered snPTV, one was a high common iliac node that extended 2 mm beyond the treatment field superiorly and the second was a para-aortic node located at the L4 vertebral body level and was entirely outside the treatment field. Overall, the majority of SLNs identified were covered by radiation pelvic fields. However, conventional treatment fields were more likely to leave SLNs uncovered compared to 3D-CRT or IMRT treatment plans, with greater than 95% of snPTV regions adequately covered using 3D-CRT and IMRT volumes. In 2 cases involving high common iliac and para-aortic nodes, the expanded superior border in the IMRT and 3D-CRT plans still placed the snPTV outside of the treated volume.

To Treat Pelvic Nodes or Not: Could the Greater Testicular Scatter Dose From Whole Pelvic Fields Confound Results of Prostate Cancer Trials?

To Treat Pelvic Nodes or Not: Could the Greater Testicular Scatter Dose From Whole Pelvic Fields Confound Results of Prostate Cancer Trials?

Results of 9 Years of IMRT Quality Assurance in a French Comprehensive Cancer Center

Intensity-modulated radiation therapy (IMRT) presents a challenge in terms of quality assurance (QA) measurements. Even if no gold standard exists to validate QA results, ion chamber (IC) and dosimetric films still play an important role. Since 2001, more than 800 patients have been treated with IMRT for Head and Neck (H&N), prostate, and anal cancer in our cancer. We present here our QA results combining both methods. All patients were treated using a sliding window technique with a 120 multi-leaves collimator (MLC, Varian Linac). IMRT optimization was done using the Helios inverse planning software. Plans were validated before treatment by comparing the computed dose in a composite plan created in a phantom with the absolute and relative measurements in the same phantom. The real gantry angles were used for computation and measurements for the first 30 H&N patients compared to a fixed (0 deg) gantry angle. Absolute isocenter measurements were done in phantoms (square or cylindrical) using IC with a 0,125 cc detection volume connected to dosimeters (Unidos PTW). Relative dose was measured using 2D dosimetric film (Kodak XomatV) the first years and the EDR2 film thereafter. A calibration curve was systematically created in all series of films to obtain more complete data on absolute dose than allowed by the IC. 190 H&N field measurements with the gantry in real treatment position were made. The mean difference between computed and measured dose at isocenter for each field was 0.72% ± 3.2 (± 1 SD). With gantry fixed at 0°, this difference was 1.33% ± 3.2 for 808 H&N fields, 0.07 ± 1.2 for 2319 prostate fields, and 0.37% ± 0.62 for 108 prostate fossa fields. More complex pelvic fields for locally advanced prostate and anal canal cancers resulted in mean differences of 0.49% ± 1.9 for 26 fields and 2.07% ± 2.8 for 109 fields, respectively. The mean difference between computed and measured dose at isocenter for the sum of all fields of each patient was 0.05% ± 0.9 for 383 prostate cases, 1.49% ± 1.9 for 158 H&N cases, 0.37% ± 0.3 for 23 cases of prostatic fossa, 0.80% ± 0.3 for 4 cases of prostate treated with pelvic fields, and 2.31% ± 0.6 for 17 cases of anal canal cancer. Using film dosimetry and absolute dose for the 100 first H&N patients (500 films), the mean of the point crossing a 3% gamma index and 3 mm was 92% ± 6.5. For the 300 first prostate plans, this value was 99% ± 0.8. More than 3500 IMRT beams were verified using IC +/- absolute dosimetric film before treatment delivery. This QA method validates the reliability of the TPS and Linac and could help physicians for implementing IMRT in their center.

Coverage of pelvic lymph nodes in conventional pelvic radiation for cervical cancer

Objective To assess the coverage of pelvic lymph nodes in conventional pelvic radiation for cervical cancer. Methods Between Jan. 2005 and Mar. 2008, 56 patients with cervical cancer receiv-ing radiotherapy were enrolled in this study. The common iliac, external and internal iliac lymph nodes were delineated on the plan.ning CT images. The borders of conventional pelvic irradiation fields were copied to the sagittal and coronal images of digital reconstruction. Anterior-posterior fields (AP) :superior border was the inferior border of L 4 ;inferior border was the inferior border of the obturator foramen;and lateral borders were 15 mm lateral to The bone pelvic. Lateral fields (LAT) :anterior border was anterior to the symphysis pubis;posterior border was the posterior border of the sacrum. Distances were measured between the bifurcation of the aorta and superior border, between the bifurcation of the common iliac artery and lateral border of the AP field, and between the external iliac artery and anterior border of the LAT field. The radiation fields were de-fined as adequate, undersize and oversize when the distances were 15-20 mm, less than 15 mm and more than 20 mm, respectively. Results Superiorly, the common iliac lymph nodes were missed in 98% pa-tients, oversize fields found in 2%, and at least one side of the internal or external iliac lymph nodes missed in 14%. Laterally, the external iliac lymph nodes were missed in 41% patients, and oversize fields found in 11%. Anteriorly, the external iliac lymph nodes were missed in 43% patients, and oversize fields found in 25%. Conclusions Conventional pelvic radiation fields according to the bone markers may miss the pelvic lymph nodes, especially the internal iliac lymph nodes. The target nodes should be delineated individually based on CT or MRI to guarantee their coverage in radiotherapy. Key words: Cervical neoplasms/radiotherapy; Tomography; X-ray computed; Lymph nodes; overlay

Incidental Testicular Irradiation From Prostate IMRT: It All Adds Up

To identify the technical aspects of image-guided intensity-modulated radiation therapy (IMRT) for localized prostate cancer that could result in a clinically meaningful incidental dose to the testes. We examined three sources that contribute incidental dose to the testes, namely, from internal photon scattering from IMRT small field and large pelvic nodal fields with 6 or 15 MV, from neutrons when >10-MV photons are used, and from daily image-guided fiducial-based portal imaging. Using clinical data from 10 patients who received IMRT for prostate cancer, and thermo-luminescent dosimeter measurements in phantom, we estimated the dose to the testes from each of these sources. A mean testicular dose of 172 and 220 cGy results from internal photon scatter for pelvic nodal fields and 68 and 93 cGy for prostate-only fields, for 6- and 15-MV energies, respectively. For 15-MV photon energies, the mean testicular dose from neutrons is 60 cGy for pelvic fields and 31 cGy for prostate-only fields. From daily portal MV image guidance, the testes-in-field mean dose is 350 cGy, whereas the testes-out-of-field scatter dose is 16 cGy. Dosimetric comparisons between IMRT using 6-MV and 15-MV photon energies are not significantly different. Worst-case scenarios can potentially deliver cumulative incidental mean testicular doses of 630 cGy, whereas best-case scenarios can deliver only 84 cGy. Incidental dose to the testes from prostate IMRT can be minimized by opting to restrict the use of elective pelvic nodal fields, by choosing photon energies <10 MV, and by using the smallest port sizes necessary for daily image guidance.

A Phase II evaluation of weekly topotecan as a single agent second line therapy in persistent or recurrent carcinoma of the cervix: A Gynecologic Oncology Group study

Purpose To estimate antitumor activity and toxicity of weekly topotecan hydrochloride in patients with persistent or recurrent cervical carcinoma who failed prior treatment. Patients and methods Women entered on study had or failed one prior chemotherapy regimen in addition to radiosensitizing chemotherapy, performance status less than 3, and adequate hematologic, renal, hepatic, and neurological function. Topotecan was infused at 3.0 mg/m 2 on days 1, 8, and 15 every 28 days. Results Twenty-seven patients were enrolled onto this study with 25 evaluable. Twenty-two patients had received radiation and chemotherapy prior to study. A median of two and mean of three courses of chemotherapy was given (range, one to eight courses). The most frequently severe adverse events were grade 3 anemia (28%) and grade 4 (4%) along with grade 3 neutropenia (8%) and grade 4 (8%). Two patients had grade 4 thrombocytopenia. There were no complete or partial responders. Ten patients (40%) had stable disease, twelve (48%) had increasing disease, and response could not be assessed in three (12%). The median progression-free survival was 2.4 months for the patients with increasing disease and 6.2 months (3.5–8.8 months) for those with stable disease. Disease location was equally divided within and outside the irradiated field. The 12 patients with increasing disease were more likely to have disease outside the pelvic radiation field. Conclusion There were no complete or partial responders to weekly topotecan among the 25 patients in this study.